I apologize for the delayed response, but i was impeded.
Regarding your question about testing the component, if you wish I can test it on a copy of my site with "The download archive currently contains 34,952 downloads in 1,998 categories." and / or pure Joomla. That's what I can do when I have free time and opportunity.
On the topic: There is also a bug in the "Category list box"
Categories are sorted alphabetically, but referral to some categories is wrong